JPH0886317A - Bearing device - Google Patents

Abstract

PURPOSE: To prevent early deterioration of lubricating oil and further prevent excessive charging of lubricating oil between inner and outer rings of a rolling bearing especially, by flowing lubricating oil to the side of the bearing and cooling the bearing. CONSTITUTION: A metal and double-structured lubricating oil introduction tube 12 is embedded in a bearing housing 7. A center hole serves as an oil introduction hole 13. Operation fluid 15 which varies in two phases of air and liquid is sealed in a circular space outside thereof, and a heat pipe is provided. A tapered surface 10a is formed on an outer periphery of a shaft nut 10 which fastens and fixes an inner ring 8b of a ball bearing 8 to a rotary shaft 9. A lubricating oil discharging port 16 on a lower end opening of the oil introduction hole 13 is formed inside a bearing housing 7 so as to be positioned upward of the tapered surface 10a. Grease inside the oil introduction hole 13 is heated by the operation fluid 15 which is evaporated by the heat of the ball bearing 8, loosing its viscosity, and dropped to the tapered surface 10a. It is flowed to the side of the ball bearing 8 by the centrifugal force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device having a lubricating oil guide tube for supplying lubricating oil to the bearing side.

[0002]

2. Description of the Related Art A bearing supports a rotating shaft to hold it in a predetermined position and ensures smooth rotation of the shaft while receiving the weight of the shaft and the load acting on the shaft. .
Losses such as friction, wear, and heat are generated in the bearing due to the external force that acts, but it is necessary to lubricate the bearing with lubricating oil, such as grease, for the purpose of reducing these losses and improving machine efficiency and extending the service life. . For this refueling, generally, a method is provided in which a lubricating oil guide pipe is provided in a bearing housing having a bearing mounted therein, and grease is supplied from the lubricating oil guide pipe. The lubricating oil guide pipe is manually filled with grease at regular intervals and pushed into the bearing side.

[0003]

However, in the above-mentioned structure, since the grease is manually supplied, the supply amount is unstable, and if the grease is filled too much, the grease is tightly packed in the lubricating oil supply passage and smoothly. It will not flow to the bearing side, and the grease supply to the bearing will be insufficient. On the other hand, although the bearing generates heat as the rotary shaft rotates, the conventional bearing device has a low heat radiation property, and thus the grease is deteriorated early under the influence of the heat.

Further, when the bearing is a ball bearing, if grease is excessively supplied to the lubricating oil supply passage, the grease is filled between the outer ring and the inner ring, and the rotation between the inner and outer rings is accompanied by the rotation of the rotating shaft (inner ring). The balls existing in the ball will start rolling while stirring the grease, adding extra rotational resistance to the rotating shaft and increasing the power loss.

The present invention has been made in view of the above circumstances, and an object thereof is to smoothly flow lubricating oil to the bearing side even if the lubricating oil is tightly packed in an oil guide hole for guiding the lubricating oil to the bearing side. The bearing can be cooled and the lubricating oil can be prevented from prematurely deteriorating. Furthermore, even if the bearing is a rolling bearing such as a ball bearing, the lubricating oil is not likely to be excessively packed between the inner and outer rings. To provide the equipment.

[0006]

In order to solve the above-mentioned problems, the bearing device of the present invention comprises a bearing housing having a bearing for supporting a rotary shaft mounted therein, a double tubular body and a central hole. An oil guide hole is provided, and a lubricating oil guide tube in which a working liquid that changes in phase between gas and liquid is enclosed is provided in an annular space outside the oil guide hole, and one end of the lubricating oil guide tube is embedded in the bearing housing. Then, the lubricating oil accumulated in the oil guide hole is supplied to the bearing side (Claim 1). In this case, a plurality of fins may be provided on the outer circumference of the other end of the lubricating oil guide pipe (claim 2). Further, it is preferable that a tapered lubricating oil guide portion that guides the lubricating oil supplied from the lubricating oil guide pipe to the bearing is provided on the rotating shaft (claim 3). Further, it is preferable that the lubricating oil guide pipe is provided with an oil level gauge (claim 4). Further, it is preferable that the other end side of the lubricating oil guide tube is formed to have a large diameter (claim 5).

[0007]

According to the bearing device of the present invention, the lubricating oil guide tube absorbs heat of the bearing and the bearing housing by the phase change effect of the working liquid in the annular space to suppress the temperature rise, and the absorbed heat causes the oil to flow. Since the lubricating oil held in the guide hole is appropriately warmed, the lubricating oil has a reduced viscosity and is supplied to the bearing side. According to the bearing device of the second aspect, since the surface area is increased by the large number of fins provided on the outer circumference of the other end of the lubricating oil guide pipe, the vaporized working liquid in the annular space is cooled more efficiently. .

According to the third aspect of the bearing device, the tapered lubricating oil guide portion provided on the rotating shaft efficiently guides the lubricating oil supplied from the lubricating oil guide pipe to the bearing side. According to the bearing device of the fourth aspect, since the lubricating oil guide pipe is provided with the oil level gauge, the remaining amount of the lubricating oil can be confirmed, and the lubricating oil supply timing can be predicted. According to the bearing device of the fifth aspect, since the other end side of the lubricating oil guide pipe is formed to have a large diameter, the surface area is increased.
The working liquid vaporized in the annular space is cooled more efficiently. If the oil guide hole is also formed to have a large diameter, the capacity of the lubricating oil increases.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an electric motor as a rotary electric machine will be described below with reference to FIGS. FIG. 1 is a vertical cross-sectional view of the vicinity of a bearing device of an electric motor. First, the structure of the electric motor main body will be described. The outer shell of the electric motor is composed of a stator frame 1 and a bearing bracket 2, and the stator frame 1 and the bearing bracket. Cooling fins 3, 4 on the outer surface of 2
Are formed. A stator iron core 5 is attached to the inner peripheral surface of the stator frame 1, and a stator winding 6 is attached to the stator iron core 5.
Is installed. The center of the bearing bracket 2 is configured as a bearing housing 7, and a rolling bearing as a bearing, for example, a ball bearing 8 is mounted inside the bearing housing 7, and a rotary shaft 9 is rotatably supported by the ball bearing 8. There is.

In this case, the outer ring 8a of the ball bearing 8 is fitted and fixed to the bearing housing 7, and the inner ring 8b is fastened and fixed to the rotary shaft 9 by a shaft nut 10 screwed to the rotary shaft 9. The outer peripheral surface of the shaft nut 10 is tapered, and the tapered surface 10a forms a groove with an annular projection 10b provided at the end of the ball bearing 8 of the shaft nut 10 opposite to the inner ring 8b side. The diameter is increased toward the inner ring 8b of the ball bearing 8, and the maximum diameter portion thereof is set to be larger than the outer diameter of the inner ring 8b and smaller than the inner diameter of the outer ring 8a. It has the same diameter as the outer diameter of the inner ring. The tapered surface 10a of the shaft nut 10 serves as a lubricating oil guide portion. A rotor iron core 11 is attached to the rotating shaft 9, and when the stator winding 6 is energized, a rotating torque is generated in the rotor iron core 11 by its electromagnetic force and the rotating shaft 9 is rotated. .

Now, in order to supply the lubricating oil to the ball bearing 8 side, the lower end which is one end of the lubricating oil guide tube 12 is embedded in the bearing housing 7. The lubricating oil guide pipe 12 is made of metal and has a double tubular shape, and the central hole is an oil guide hole 13,
An annular space 14 outside the oil guide hole 13 is filled with a working liquid 15 that undergoes a phase change between gas-liquid two phases and is configured as a heat pipe. The lower end opening of the oil guide hole 13 of the lubricating oil guide tube 12 serves as a lubricating oil discharge port 16, and the bearing housing 7 is positioned so as to be located above the tapered surface 10a of the shaft nut 10.
It has an opening inside. Further, an oil drainer 17 is attached to an end surface of the bearing housing 7 extending toward the rotor core 11, and lubricating oil that is dripped from the lubricating oil discharge port 16 to the tapered surface 10a and guided to the ball bearing 8 is provided in the bearing housing. 7
To prevent it from leaking.

An upper end portion of the lubricating oil guide tube 12 is formed to have a large diameter to form a lubricating oil holding portion 18, and a lid 20 having an oil supply nipple 19 at a substantially central portion is fixed to an upper surface of the lubricating oil holding portion 18. There is. A plurality of fins 21 are provided on the outer circumference of the lubricating oil holding portion 18, and pass from the cooling fan (not shown) between the cooling fins 3 of the stator frame 1 and between the cooling fins 4 of the bearing bracket 2 as indicated by arrow 22. The cooling air that is sent is hit. A transparent or semi-transparent oil level gauge 23 made of glass, plastic or the like is mounted on the wall surface of the lubricating oil retention section 18, and the amount of oil in the lubricating oil retention section 18 can be checked through the oil level gauge 23. You can do it.

Next, the operation of this embodiment will be described. When the electric motor is energized, the stator winding 6 is energized, and its electromagnetic force generates a rotational torque in the rotor core 11,
The rotating shaft 9 rotates. When the rotation of the rotary shaft 9 causes heat to be generated in the ball bearing 8 due to loss such as friction loss, and the temperature of the vicinity of the ball bearing 8 and the temperature of the bearing housing 7 rises, the operation in the annular space 14 of the lubricating oil guide pipe 12 is performed. The liquid 15 takes heat and vaporizes, and is cooled and liquefied again by the cooling air flowing between the cooling fins 3 and 4 of the stator frame 1 and the bearing bracket 2 in the vicinity of the lubricating oil holding portion 18. At this time, the lubricating oil holding portion 18
Is formed by enlarging the upper end portion of the lubricating oil guide tube 12 to have a large surface area and the lubricating oil holding portion 1
Since a plurality of fins 21 are provided on the outer circumference of 8 to further increase the surface area, the vaporized working liquid 15 in the annular space 14 is efficiently cooled by the cooling air flowing between the cooling fins 3 and 4. It undergoes a phase change to liquid and cools the bearing housing 7 and thus the ball bearing 8.

At the same time, the gas in the annular space 14 also gives heat to the lubricating oil held in the oil guide hole 13, in this case grease, so that the grease is appropriately warmed and its viscosity drops to half. The liquid becomes liquid and an appropriate amount is dropped from the lubricating oil discharge port 16. At this time, the grease falls on the tapered surface 10a of the shaft nut 10 and the rotating shaft 9
Is smoothly flowed to the bearing 9 side by the centrifugal force caused by the rotation of and is supplied between the inner and outer races 8a and 8b.

When the grease in the oil guide hole 13 becomes semi-liquid and is dripped from the lubricating oil discharge port 16, the liquid level of the grease gradually decreases. This liquid level is displayed on the oil level gauge 23, and if the remaining amount of grease is low, the refueling nipple 1
The grease is replenished from 9 to the lubricating oil holding portion 18. Since the lubricating oil holding portion 18 is formed by increasing the diameter of the upper end portion of the lubricating oil guide pipe 12 and has a large capacity, a large amount of grease can be stored.

As described above, according to this embodiment, since the ball bearing 8 can be cooled by the working liquid 15, it is effective that the grease supplied to the ball bearing 8 is exposed to a high temperature atmosphere and deteriorates early. Can be prevented. Moreover, even if the grease is tightly packed in the lubricating oil guide tube 12, the grease is heated by the working liquid 15 and its viscosity is lowered to improve the fluidity, so that the grease is clogged on the way and the ball bearing 8 is not filled. The grease can be smoothly supplied to the ball bearing 8 for a long period of time without fear of stopping the supply.

Further, in the oil supply system of this embodiment, the lubricating oil is not supplied directly from the lubricating oil guide tube 12 between the inner and outer wheels 8a and 8b of the ball bearing 8 but is heated to reduce the viscosity, so that the lubricating oil The grease flowing out from the guide pipe 12 is indirectly passed through the tapered surface 10a to indirectly rotate both the inner and outer wheels 8a and 8b of the ball bearing 8.
Since it is a method of supplying the grease in the space, even if the lubricating oil guide pipe 12 is overfilled, the situation that the grease is filled between the inner and outer wheels 8a and 8b does not occur. Therefore, it is possible to prevent a situation in which a ball 8c, which is a rolling element provided between the inner and outer wheels 8a and 8b, rolls while stirring the grease to cause power loss.

Further, since the surface area of the upper end portion of the lubricating oil guide tube 12 is increased by the plurality of fins 21 provided on the outer periphery of the lubricating oil holding portion 18, the working fluid 15 vaporized by depriving heat is cooled by the cooling fins 3, 3. Since it is efficiently cooled by the cooling air flowing between the four bearings, the temperature rise of the ball bearing 8 and the bearing housing 7 is further suppressed, and the early deterioration of the grease supplied into the ball bearing 8 is prevented more effectively. can do.

Furthermore, the inner ring 8a of the ball bearing 8 is attached to the rotary shaft 9.
A shaft nut 10 for tightening and fixing the shaft nut 10 is screwed, and the grease dropped from the lubricating oil discharge port 17 drops on the tapered surface 10a provided on the outer peripheral surface of the shaft nut 10,
The centrifugal force smoothly flows between the inner and outer wheels 8a and 8b of the ball bearing 8, so that the grease can be supplied to the ball bearing 8 without retaining the grease even with a simple structure.

In addition, since the oil level gauge 23 is provided, it is possible to confirm the remaining amount of grease, and it is possible to predict the lubricating oil supply timing. Further, since the upper end portion of the lubricating oil guide pipe 12 is formed to have a large diameter, the surface area is increased, so that the cooling effect is enhanced, and if the oil guide hole 13 is also made large, the lubricating oil for storing the lubricating oil is stored. The holding portion 18 can be used, and the number of times of replenishing the lubricating oil can be reduced.

The present invention is not limited to the embodiments described above and shown in the drawings, but the following expansions or modifications are possible. The space C in the bearing housing 7 communicating with the gap between the inner and outer wheels 8a and 8b of the ball bearing 8 as the lower end opening of the lubricating oil guide pipe 12 faces the lubricating oil (grease) dripping from the lubricating oil guide pipe 12. The lubricating oil guide portion (taper surface 10a) for locating the tapered surface 10a that guides between the inner and outer wheels 8a and 8b functions as an arrangement space, and this arrangement space is provided in the space D between the ball bearing 8 and the oil drainer 17. You may change. The tapered surface 10a may be directly formed on the rotation shaft.
The ball bearing 8 may be replaced with another rolling bearing, for example, a roller bearing or the like, or may be replaced with a sliding bearing. The present invention is not limited to bearing devices for electric motors, and may be applied to bearing devices in general.

[0022]

As is apparent from the above description, the bearing device of the present invention has the following excellent effects.
According to the means as set forth in claim 1, the lubricating oil guide pipe is formed into a double pipe, and the working liquid that undergoes a phase change between gas-liquid two phases is enclosed in the annular space on the outer periphery and embedded in the bearing housing.
This working fluid removes heat from the bearings and bearing housing and vaporizes, and the temperature rise in the vicinity of the bearings is suppressed to prevent early deterioration of the lubricating oil. Is warmed to a low viscosity,
Since it becomes semi-liquid and an appropriate amount is dropped to the bearing side, it is possible to prevent insufficient or excessive supply of lubricating oil to the bearing, especially when the bearing is a rolling bearing, power loss due to excessive supply of lubricating oil It can be prevented.

According to the second aspect of the present invention, by providing a plurality of fins on the outer circumference of the other end of the lubricating oil guide pipe, the surface area of the upper end of the lubricating oil guide pipe increases, so that the bearing and the bearing housing. The working liquid vaporized by removing the heat is efficiently cooled by the cooling air flowing between the cooling fins of the stator frame, and the cooling effect of the bearing and the bearing housing by the lubricating oil guide tube can be made more effective.

According to the third aspect of the invention, since the lubricating oil guide portion is provided on the rotary shaft, the lubricating oil supplied from the lubricating oil guide pipe is efficiently guided to the bearing side. According to the means described in claim 4, it is possible to confirm the remaining amount of the lubricating oil in the lubricating oil guide tube by the oil level gauge, and to predict the lubricating oil supply timing. According to the means described in claim 5, if the other end of the lubricating oil guide pipe is formed to have a large diameter, the surface area becomes large, so that the cooling effect can be improved, and if the inner diameter of the oil guide hole is also made larger, the lubricating oil Since the capacity is increased, it is possible to reduce the number of times of lubricating oil supply.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of the vicinity of a bearing device for an electric motor according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a lubricating oil holding portion that is an upper end portion of the lubricating oil guide pipe.

[Explanation of symbols]

7 is a bearing housing, 8 is a ball bearing (bearing), 10 is a shaft nut, 12 is a lubricating oil guide tube, 13 is an oil guide hole, 14 is an annular space, 15 is a working liquid, and 23 is an oil level gauge.

Claims (5)

[Claims] 1. A bearing housing in which a bearing for supporting a rotary shaft is mounted, and a double-tubular structure, wherein a central hole is an oil guide hole, and a gas-liquid mixture is provided in an annular space outside the oil guide hole. A lubricating oil guide tube enclosing a working liquid that changes phase between phases, one end of the lubricating oil guide tube is embedded in the bearing housing, and the lubricating oil stored in the oil guide hole is provided on the bearing side. Bearing device configured to supply. 2. The bearing device according to claim 1, wherein a plurality of fins are provided on the outer circumference of the other end of the lubricating oil guide pipe. 3. The bearing device according to claim 1 or 2, wherein a tapered lubricating oil guide portion for guiding the lubricating oil supplied from the lubricating oil guide pipe to the bearing is provided on the rotary shaft. 4. The bearing device according to claim 1, wherein the lubricating oil guide tube is provided with an oil level gauge. 5. The bearing device according to claim 1, wherein the other end side of the lubricating oil guide tube is formed to have a large diameter.